Triazole/arylamine-modified sulfonates as multifunctional additives for lubricants

ABSTRACT

Reaction products of aryltriazoles or arylamines and arylsulfonic acids pre-reacted or formed in-situ in lubricants provide multifunctional antioxidant, antiwear and corrosion-inhibiting properties thereto.

BACKGROUND OF THE INVENTION

This invention is directed to triazole/arylamine-modified sulfonates asmultifunctional lubricant additives and to lubricant compositionscontaining same.

Metallic aryl sulfonates such as calcium dinonylnaphthalene sulfonateshave been widely used in petroleum and synthetic lubricants as rust andcorrosion inhibiting additives. Additionally, these and related metallicaryl sulfonates have, on occasion, provided good detergency anddemulsibility properties in a variety of lubricant formulations.

Lubricant in service applications often generate acid species oracid-forming species, especially when exposed to high operatingtemperatures, extended service life and/or contact with atmosphericoxygen during aeration caused by churning or moving elements of thelubricated machine. Acid-forming species can also be formed viahydrolysis, thermal decomposition, or other similar mechanisms.

If metallic arylsulfonates are used as additives in such systemsdescribed above, neutralization or acidification to form sulfonic acidscan occur. If both metallic aryl sulfonates and aryltriazoles orarylamines are used together in a lubricant, or alternativelypre-reacted, these arylsulfonic acids and aryltriazoles or arylaminescan react to form sulfonamides or sulfonium salts.

SUMMARY OF THE INVENTION

This application discloses and is more particularly directed to thereaction products of aryltriazoles or arylamines and arylsulfonic acidspre-reacted, or formed in-situ in lubricants, made by incorporatinghydrocarbyltriazoles or arylamines onto the backbone of arylsulfonicacids, to provide multifunctional antioxidant, antiwear, and corrosioninhibiting properties. This application is also directed to improvedantioxidant, antiwear and corrosion-inhibiting lubricant compositions.Additional properties expected when used in lubricants and/or fuels areantifatigue, antirust extreme pressure, cleanliness, detergency,dispersancy, thermal stabilities and demulsifying or emulsifyingproperties.

The product of the present invention can be made by the direct reactionof partially neutralized or acidified metallic arylsulfonates andarytriazoles or arylamines. The arylsulfonates may be acidified orneutralized by means of small quantities of inorganic acids or by acidhalides or formed in service or in-situ.

The use of reaction products of acidified sulfonates and aryltriazolesor arylamines as multifunctional antioxidant/antiwear/anticorrosionlubricant additives to the best of applicants' knowledge has not beenreported in the literature and is believed to be novel. The compositionof matter, lubricant compositions containing such additives, and the useof such reaction products in lubricants to improve the performanceproperties are all believed to be unique and unobvious.

It is, therefore, an object of this invention to provide improvedlubricant compositions, novel multifunctional lubricant additives, andthe use of the herein described novel additive products of reaction insuch compositions.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Metallic hydrocarbyl aryl sulfonates can be neutralized in service, insitu, or via addition of small quantities of organic or inorganic acids,as shown below:

    ArSO.sub.3 M+H.sup.+ →ArSO.sub.3 H

Where Ar is dialkylnaphthalene, or dihydrocarbylarenes, or monoalkyl ormonohydrocarbylarenes, and M is alkali, or alkaline-earth metal and/or anitrogenous group such as amine or ammonium.

Any appropriate hydrocarbyl triazole selected from cyclic, acyclic,hydrocarbyl substituted, alkyl or aryl triazoles can be used herein.Preferred are aryltriazoles. Arylamines include primary and secondaryamines, such as anilines, alkylated anilines, naphthylamines, alkylatednaphthylamines, diphenylamines, dinaphthylamines,N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine,N-aryl-1-napthylamines, N-aryl-1-alkylnapthylamines,N-aryl-2-napthylamines, N-aryl-2-alkylnaphthylamines and the like. Thepreferred arylamines are N-aryl-1-naphthylamines.

Alternatively, metallic aryl sulfonates may neutralize or acidify toform arylsulfonic acids, which can then be converted to arylsulfonylhalides, with inorganic acid chlorides, such as is thionyl chloride.Arylsulfonyl chlorides thus formed can react with aryltriazoles to giveonly the corresponding sulfonamides and avoid the sulfonium salts asshown in Example 3.

Conditions for the above reactions may vary widely depending uponspecific reactants, the presence or absence of a solvent and the like.Any suitable set of reaction conditions known to the art may be used.Hydrocarbon solvents such as toluene or xylenes are frequently used.

Generally stoichiometric or equimolar ratios of reactants are used.However, more than molar or less than molar amounts may be used. In anyevent, reaction conditions are not viewed as critical.

The additives embodied herein are utilized in lubricating oil or greasecompositions in an amount which imparts significantantioxidant/antiwear/anticorrosion characteristics to the oil or greaseas well as reducing the friction of engines operating with the oil inits crankcase. Concentrations of about 0.001 to about 10 wt. % based onthe total weight of the composition can be used. Preferably, theconcentration is from 0.1 to about 3 wt. %.

The additives can also be used in hydrocarbon fuels, oxygenated fuels,and mixtures at concentration of from about 0.00001% to about 0.1% byweight based on the total weight of the fuel composition.

The additives have the ability to improve the antioxidant/antiwearcharacteristics of various oleagenous materials such as hydrocarbyllubricating media which may comprise liquid oils in the form of either amineral oil or a synthetic oil, or mixtures or mineral oils and orsynthetic oils, or in the form of a grease in which the aforementionedoils are employed as a vehicle.

In general, mineral oils, both paraffinic, naphthenic and mixturesthereof, employed as the lubricant, or grease vehicle, may be of anysuitable lubricating viscosity range, as for example, from about 45 SSUat 100° F. to about 6000 SSU at 100° F. and preferably, from about 50 toabout 250 SSU at 210° F. These oils may have viscosity indexes rangingto about 95 or greater wherein the average molecular weights may rangefrom about 250 to about 800. Where the lubricant is to be employed inthe form of a grease, the lubricating oil is generally employed in anamount sufficient to balance the total grease composition, afteraccounting for the desired quantity of the thickening agent, and otheradditive components to be included in the grease formulation.

A wide variety of materials may be employed as thickening or gellingagents. These may include any of the conventional metal salts or soaps,which are dispersed in the lubricating vehicle in grease-formingquantities in an amount to impart to the resulting grease compositionthe desired consistency. Other thickening agents that may be employed inthe grease formulation may comprise the non-soap thickeners, such assurface-modified clays and silicas, aryl ureas, calcium complexes andsimilar materials. In general, grease thickeners may be employed whichdo not melt and dissolve when used at the required temperature within aparticular environment; however, in all other respects, any materialswhich is normally employed for thickening or gelling hydrocarbon fluidsfor foaming grease can be used in preparing grease in accordance withthe present invention.

In instances where synthetic oils, or synthetic oils employed as thelubricant or vehicle for the grease, are desired in preference tomineral oils, or in combination therewith, various compounds of thistype may be successfully utilized. Typical synthetic oils include, butare not limited to, polyisobutylene, polybutenes, hydrogenatedpolydecenes, polypropylene glycol, polyethylene glycol, trimethylpropaneesters, neopentyl and pentaerythritol esters, di(2-ethylhexyl) sebacate,di(2-ethylhexyl) adipate, dibutyl phthalate, fluorocarbons, silicateesters, silanes, esters of phosphorus-containing acids, liquid ureas,ferrocene derivatives, hydrogenated synthetic oils, chain-typepolyphenyls, siloxanes and silicones (polysiloxanes), alkyl-substituteddiphenyl ethers typified by a butyl-substituted bis(p-phenoxy phenyl)ether, phenoxy phenylethers.

It is to be understood, however, that the compositions contemplatedherein can also contain other materials. For example, corrosioninhibitors, extreme pressure agents and the like can be used asexemplified respectively by metallic phenates, sulfonates, carboxylates,salicylates, polymeric succinimides, esters, amides and/or imides,non-metallic or metallic phosphorodithioates and the like. Thesematerials do not detract from the value of the compositions of thisinvention, rather the materials serve to impart their customaryproperties to the particular compositions in which they areincorporated.

The following examples are merely illustrative and not meant to belimitations.

EXAMPLE 1

Approximately 192 g of calcium dinonylnaphthalene sulfonate(commercially obtained from King Industries, Inc. as Nasul 729) and 100ml of toluene were charged to a one-liter, four-neck flask equipped withcondenser, thermometer, nitrogen sparger and mechanical stirrer, towhich 8 ml of 30% sulfuric acid was added and stirred at 70° C. for onehour. A solution of tolyltriazole (26.6 g, 0.20 mol) in 50 ml of toluenewas introduced and the mixture was heated to reflux for four hours. Theresulting reaction mixture was filtered. The filtrate was washed withwater and evaporated under a reduced pressure at 130° C. to yield 215 gof viscous brown fluid.

EXAMPLE 2

Under the exact same reaction conditions as described in Example 1, thecalcium sulfonate was acidifed and reacted with N-phenyl-1-napthylamine(44 g, 0.20 mol). Approximately 234 g of viscous dark greenish brownfluid was obtained as the final product.

EXAMPLE 3

Under the same general reaction conditions as described in Example 1,approximately 192 g of calcium sulfonate was acidified with 8 ml of 30%sulfuric acid at 70° C. for one hour, and the reaction mixture washeated up to reflux to distill off the aqueous portion in a Dean-Starktrap. The reaction mixture was then cooled to 70° C., to which asolution of thionyl chloride. (24,8 g, 0.21 mol) in 30 ml of toluene wasadded dropwise. The resulting mixture was stirred for one hour at 70° C.after addition. Finally, a solution of tolyltriazole (26.6 g, 0.20 mol)in 50 mol of toluene was introduced and the mixture was heated to refluxfor four hours. 220 g of dark brown fluid was obtained as the finalproduct.

Evaluation of Products

The products of the examples were blended into solvent paraffinicneutral mineral oil and evaluated by Catalytic Oxidation Test (Table 1).Confirmation of the antiwear properties is shown by Four-Ball Wear Test(Table 2).

Basically, in the catalytic oxidation test, the lubricant is subjectedto a stream of air which is bubbled through at the rate of five litersper hour at elevated temperatures for a specified time (Table 1, 325° F.for 40 hours). Present in the composition are samples of metals commonlyused in engine construction, namely, iron, copper, aluminum, and lead.See U.S. Pat. No. 3,682,980, incorporated herein by reference.

                  TABLE 1                                                         ______________________________________                                        Catalytic Oxidation Test                                                      (325° F., 40 hr)                                                                       Change In  Percent Change In                                                  Acid Number                                                                              Kinematic Viscosity                                Item            Δ TAN                                                                              Δ KV %                                       ______________________________________                                        Base oil (100% solvent                                                                        15.79      211.0                                              paraffinic neutral mineral                                                    oil)                                                                          1% Example 1 in above                                                                         0.26       29.3                                               base oil                                                                      1% Example 2 in above                                                                         0.63       5.3                                                base oil                                                                      1% of Example 3 in above                                                                      0.09       1.0                                                base oil                                                                      ______________________________________                                    

The remarkable antioxidant performance of these reaction products isevident, as demonstrated by excellent control of increases in bothacidity and viscosity.

In the Four-Ball Wear Test, three stationary balls are placed in thelubricant cup and the lubricant containing the compound to be tested isadded thereto, and a fourth ball is placed in a chuck mounted on adevice which can be used to spin the ball at known speeds and loads. Thesamples were tested using 1/2 inch stainless steel balls of 52100 steelfor 30 minutes.

                  TABLE 2                                                         ______________________________________                                        Four-Ball Wear Test                                                           (40 kg load, 200° F., 2000 rpm, 30 min)                                Item                Wear Scar Diameter, mm                                    ______________________________________                                        Base oil (80% solvent paraffinic                                                                  1.72                                                      bright, 20% solvent paraffinic                                                neutral mineral oils)                                                         1% of Example 1 in above base oils                                                                0.55                                                      1% of Example 2 in above base oils                                                                0.75                                                      1% of Example 3 in above base oils                                                                0.52                                                      ______________________________________                                    

The results of the Four-Ball Wear Tests clearly show good antiwearactivity of these reaction products. The use of additive concentrationsof reaction products of the above disclosed compositions in premiumquality industrial, automotive and marine lubricants will provideimproved multifunctional antioxidant/antiwear/anticorrosion propertiesto such compositions.

What is claimed is:
 1. A product of reaction having multifunctionalantiwear/antioxidant/anticorrosion characteristics when admixed withvarious lubricating media prepared by reacting hydrocarbyl triazolesselected from a cyclic, hydrocarbyl substituted alkyl or aryltriazolesor arylamines selected from the group consisting of anilines, alkylatedanilines, naphthylamines, alkylated naphthylamines, diphenyl amines,dinaphthylamines, N-phenyl-1-naphthylamines, N-phenyl-2-naphthylamines,N-aryl-1-naphthylamines, N-aryl-1-alkyl-naphthylamines,N-aryl-2-naphthylamines, and N-aryl-2-alkyl-naphthylamines withneutralized or acidified metallic arylsulfonates wherein the metallicaryl sulfonate is acidified or neutralized in service, in situ or viathe reaction of small quantities of organic or inorganic acids as shownbelow:

    ArSO.sub.3 M+H.sup.+ →ArSO.sub.3 H

where Ar is a dihydrocarbylnaphthalene, dihydrocarbylarene,monohydrocarbylarene or polyhydrocarbylarene and M is an alkali oralkaline-earth metal or a nitrogenous group selected from an amine orammonium group and wherein the reaction temperature varies from ambientto slightly higher and the molar ratio of reactants varies from molar toless than molar to more than molar.
 2. The product of claim 1 comprising(1) first reacting an acidified or partially acidified metallic arylsulfonate with an inorganic acid halide and thereafter (2) reacting theresultant arylsulfonyl halide with an hydrocarbyl triazole or arylamine.3. The product of claim 2 where the inorganic halide is selected fromthe group consisting of thionyl bromide or thionyl chloride.
 4. Theproduct of claim 3 where the inorganic halide is thionyl chloride. 5.The product of claim 1 where the metallic aryl sulfonate is calciumdinonylnaphthalene sulfonate.
 6. The product of claim 1 where thearyltriazole reactant is tolyltriazole.
 7. The product of claim 1 wherethe arylamine reactant is N-phenyl-1-naphthylamine.
 8. An improvedlubricant composition consisting of a major amount of an oil oflubricating viscosity or grease prepared therefrom and a minormultifunctional antioxidant/antiwear/anticorrosion amount of a productof reaction prepared by reacting hydrocarbyl triazoles selected fromacyclic hydrocarbyl substituted alkyl or aryltriazoles or arylaminesselected from the group consisting of anilines, alkylated anilines,napthylamines, alkylated naphthylamines, diphenyl amines,dinaphthylamines, N-phenyl-1-naphthylamines, N-phenyl-2-naphthylamines,N-aryl-1-naphthylamines, N-aryl-1-alkyl-naphthylamines,N-aryl-2-naphthylamines, and N-aryl-2-alkyl-naphthylamines withacidified or neutralized metallic arylsulfonates wherein the metallicaryl sulfonate is acidified or neutralized in service, in situ or viathe reaction of small quantities of organic or inorganic acids as shownbelow:

    ArSO.sub.3 M+H.sup.+ →ArSO.sub.3 H

where Ar is a dihydrocarbylnaphthalene, dihydrocarbylarene,monohydrocarbylarene or polyhydrocarbylarene and M is an alkali oralkaline-earth metal or a nitrogenous group selected from an amine orammonium group and wherein the reaction temperature varies from ambientto slightly higher and the molar ratio of reactants varies from molar toless than molar to more than molar.
 9. The composition of claim 8 wheresaid product is prepared by (1) first reacting metallic aryl sulfonatewith an inorganic acid halide and thereafter (2) reacting the resultantarylsulfonyl halide with an hydrocarbyl triazole or arylamine.
 10. Thecomposition of claim 9 where the inorganic halide is selected from thegroup consisting of thionyl bromide or thionyl chloride.
 11. Thecomposition of claim 10 where the inorganic halide is thionyl chloride.12. The composition of claim 8 where the metallic aryl sulfonate iscalcium dinonylnaphthalene sulfonate.
 13. The composition of claim 1where the aryltriazole is tolytriazole.
 14. The composition of claim 8where the arylamine is N-phenyl-1-naphthylamine.
 15. The composition ofclaim 8 containing from about 0.001 to about 10 wt % based on the totalweight of the composition of said multifunctionalantioxidant/antiwear/anticorrosion additive product of reaction.
 16. Thecomposition of claim 8 where said lubricant is selected from (1) mineraloils, (2) synthetic oils, (3) a mixture of mineral and synthetic oils or(4) is a grease prepared from any one of (1), (2), or (3).
 17. A methodof improving the lubricity and antioxidant/antiwear/anticorrosioncharacteristics of a lubricant composition comprising adding to an oilof lubricating viscosity or grease prepared therefrom from about 0.001to about 10 wt % of the multifunctional additive product of reactiondescribed in claim 1.